The present invention relates to a lens-fitted film unit package wherein a lens-fitted film unit capable of being switched between a first EV value and a second EV value which is greater than the first EV value is packaged in a packing material, and to a method of manufacturing the lens-fitted film unit package.
The one and only exposure function in a conventional lens-fitted film unit is a combination of a fixed aperture of a camera lens and a single shutter speed, and this exposure condition is used in the daytime for photographing, while in a room or in the nighttime, the same exposure condition is used for photographing under an electronic flash, and overs and shorts of the exposure are covered by film latitude.
Further, there is available on the market a lens-fitted film unit equipped with a barrier which opens and shuts in front of a camera lens to prevent that the camera lens is soiled with dust or is scratched when the lens-fitted film unit is not used.
When photographing an object which is at a short distance such as a figure and a distant object such as a scenery in the daytime under high intensity and photographing, under electronic flash, only an object which is at a short distance such as a figure in a room under low intensity, a possibility of over-exposure or under-exposure is relatively low even when a conventional lens-fitted film unit is used.
However, under-exposure is caused when a lens-fitted film unit of this kind is used for photographing a scenery in the morning and evening where intensity is slightly low. It is therefore considered that a high speed film is loaded, which, however, makes photographing under lower intensity possible, and may cause ever-exposure in the case of high intensity.
To cope with a problem of this kind, there is disclosed in a patent publication a lens-fitted film unit wherein a camera lens having a relatively small f-number is used, and photographing is conducted with an open aperture in the case of low intensity, and a diaphragm having a small aperture is inserted in the case of high intensity, so that a distant object may be photographed with neither over-exposure nor under-exposure for a luminance range from high intensity to low intensity.
Though the aforesaid arrangement makes it possible to photograph an object under high intensity to an object under low intensity, chances of outdoor photographing under high intensity are usually much more than those of evening or indoor photographing under low intensity. Therefore, when it is possible to switch between an open aperture and a diaphragm having a small aperture as stated above, there are caused problems to get over-exposure photographs by photographing with an exposure condition for low intensity despite high intensity for the start of new photographing, and to lose a precious shutter chance by conducting switching operations.
The present invention has been achieved in view of the problems stated above, and an object of the invention is to propose a lens-fitted film unit wherein an exposure condition is always switched, for the start of new photographing, to that for high intensity which is used frequently, and switching operations for the exposure condition for low intensity are needed only for the occasion of low intensity, a lens-fitted film unit package, and a method of manufacturing the lens-fitted film unit package.
There is further given the following as another problem.
In the course of development of a lens-fitted film unit conducted by the inventors of the invention, they found out that an intended image was not photographed occasionally on the first frame of a film when the lens-fitted film unit has a switching means capable of switching between a first diaphragm and a second diaphragm whose open aperture area is smaller than that of the first diaphragm. As a result of their intensive study, the reason of the problem proved to be the following.
For example, when a lens-fitted film unit package is dropped accidentally, a shutter position is sometimes shifted by shock of the dropping. If the lens-fitted film unit has therein a means for switching diaphragms and is packaged under the condition that the diaphragm is switched to the first diaphragm having a greater aperture area, when a shutter position is shifted, there is a high possibility that the aperture portion of the diaphragm is not covered by a shutter completely. Then, it was found that if packing materials are torn under the aforesaid condition, external light enters the inner part of the lens-fitted film unit to expose a film, which is a problem.
It was also found that, when a packing material has a transparent portion, if the lens-fitted film unit is packaged under the condition that the diaphragm is switched to the first diaphragm having a greater aperture area, the external light tends to enter the inner part of the lens-fitted film unit through a clearance between a shutter and a diaphragm because of a large aperture area of the diaphragm, causing a possibility that a film is exposed, which is a problem. This problem is especially conspicuous in the mode to provide a diaphragm between a shutter and a camera lens.
The invention has been achieved in view also of this kind of problem. Namely, an object of the invention is to provide, when the lens-fitted film unit has a switching means capable of switching between a first diaphragm and a second diaphragm having an aperture area smaller than that in the first diaphragm, a lens-fitted film unit package having stable functions wherein a film is not exposed when packing materials are torn, even when the lens-fitted film unit package is dropped accidentally.
Further, an object of the invention is to provide a lens-fitted film unit package which can be preserved stably even a packing material has a transparent portion.
The objects mentioned above can be attained by either one of the following.
(1) A lens-fitted film unit package composed of a lens-fitted film unit having therein a photographic film built in beforehand, a camera lens, a shutter, a diaphragm and an EV value switching means capable of switching the EV value of the lens-fitted film unit between the first EV value and the second EV value greater than the first EV value; and a packing material; wherein the lens-fitted film unit is packaged in the packing material under the condition that the EV value of the lens-fitted film unit is switched to the second EV value.
(2) The lens-fitted film unit package according to (1) above, wherein the EV value switching means is a diaphragm switching means capable of switching a diaphragm of the lens-fitted film unit between a first diaphragm and a second diaphragm having an aperture area smaller than that of the first diagram, and the lens-fitted film unit is packaged in the packing material under the condition that the diaphragm is switched to the second diaphragm.
(3) The lens-fitted film unit package according to (1) above, wherein the EV value switching means is a shutter speed switching means capable of switching a shutter speed of the shutter between a first shutter speed and a second shutter speed which is higher than the first shutter speed, and the lens-fitted film unit is packaged in the packing material under the condition that the shutter speed is switched to the second shutter speed.
(4) The lens-fitted film unit package according to (1) above, wherein the lens-fitted film unit has a moving member which moves between a first position which makes photographing possible and a second position which makes photographing impossible, and when the moving member is moved to the second position under the condition that the lens-fitted film unit is set to the first EV value, the EV value switching means is activated to switch to the second EV value.
(5) The lens-fitted film unit package according to (4) above, wherein the moving member has a barrier member which is capable of moving in front of the camera lens, and the first position stated above is a position where the barrier member is retreated from the front part of the camera lens, and the second position stated above is a position where the front part of the camera lens is covered by the barrier member.
(6) The lens-fitted film unit package according to (1) above, wherein the lens-fitted film unit has an electronic flash unit.
(7) The lens-fitted film unit package according to (6) above, wherein charging of the electronic flash unit becomes possible when the EV value of the lens-fitted film unit is switched to the first EV value by the EV value switching means, and charging of the electronic flash unit becomes impossible when the EV value of the lens-fitted film unit is switched to the second EV value by the EV value switching.
(8) The lens-fitted film unit according to (2) above, wherein the diaphragm is provided between the camera lens and the shutter.
(9) The lens-fitted film unit according to (1) above, wherein the packing material has a transparent portion.
(10) The lens-fitted film unit according to (8) above, wherein the packing material has a transparent portion.
(11) A method of producing a lens-fitted film unit package having therein the following steps: a step to assemble a lens-fitted film unit composed of a photographic film built in beforehand, a camera lens, a shutter, a diaphragm, and an EV value switching means capable of switching between a first EV value and a second EV value which is greater than the first EV value; a step to detect the state that the EV value of the lens-fitted film unit is switched to the second EV value by the EV value switching means; and a step to package the lens-fitted film unit with a packing material when the above state is detected by the step to detect.
(12) The method according to (11) above, wherein the EV value switching means is a diaphragm switching means capable of switching the diaphragm between a first diaphragm and a second diaphragm having an aperture area smaller than that of the first diaphragm, and the lens-fitted film unit is packaged in the packing material under the condition that the diaphragm is switched to the second diaphragm.
(13) The method according to (11) above, wherein the EV value switching means is a shutter speed switching means capable of switching a shutter speed of the shutter between a first shutter speed and a second shutter speed which is higher than the first shutter speed, and the lens-fitted film unit is packaged in the packing material under the condition that the shutter speed is switched to the second shutter speed.
(14) A lens-fitted film unit equipped with a moving member which moves between a first position making photographing possible and a second position making photographing impossible, and with a diaphragm switching-means capable of switching properly between a first diaphragm which forms the maximum aperture in the course of photographing and a second diaphragm having an aperture smaller than that of the first diaphragm, and when the moving member is moved to the second position in the case of switching to the first diaphragm, the diaphragm switching means is operated to be switched to the second diaphragm.
(15) A lens-fitted film unit equipped with a moving member which moves between a first position making photographing possible and a second position making photographing impossible, and with a shutter speed switching means capable of switching properly between a first shutter speed and a second shutter speed which is higher than the first shutter speed, and when the moving member is moved to the second position in the case of switching to the first shutter speed, the shutter speed switching means is operated to be switched to the second shutter speed.
(16) A lens-fitted film unit package wherein a lens-fitted film unit equipped with a built-in electronic flash unit and with a diaphragm switching means capable of switching properly between a first diaphragm forming the maximum aperture in the course of photographing and a second diaphragm having an aperture smaller than that of the first diaphragm is packaged under the condition that the diaphragm is switched to the second diaphragm.
(17) A lens-fitted film unit package wherein a lens-fitted film unit equipped with a shutter speed switching means capable of switching properly between a first shutter speed and a second shutter speed which is higher than the first shutter speed is packaged under the condition that the shutter speed switching means is switched to the second shutter speed.
(18) A method of manufacturing a lens-fitted film unit package wherein there are provided a switched diaphragm detecting step which detects that a diaphragm switching means of a lens-fitted film unit which houses a built-in electronic flash unit and is equipped with a diaphragm switching means capable of switching properly between a first diaphragm which forms the maximum aperture in the course of photographing and a second diaphragm having an aperture that is smaller than that of the first diaphragm is switched to the second diaphragm, and a packaging step to package the lens-fitted film unit detected to be switched to the second diaphragm in the switched diaphragm detecting step.
(19) A method of manufacturing a lens-fitted film unit package wherein there are provided a switched shutter speed detecting step which detects that a lens-fitted film unit is packaged in the state that a shutter speed switching means of a lens-fitted film unit equipped with the shutter speed switching means capable of switching freely between a first shutter speed and a second shutter speed that is higher than the first shutter speed is switched to the second shutter speed, and a packaging step to package the lens-fitted film unit detected to be switched to the second shutter speed in the switched shutter speed detecting step.